44 DIPLOPODA. 
Until intermediate forms come to light, I think it expedient to keep the two genera 
distinct upon this basis. They may be contrasted as follows :— 
a. Sterna triangularly contracted between the crural acetabula, so that the coxe 
of the legs are in contact; furnished with a forwardly directed cariniform 
tubercle <6 ge ea ge a 
b. Sterna not contracted between the crural acetabula, so that the coxe of the legs 
on the right and left side are separated; not furnished with a cariniform 
tubercle ©. 2 1 2 ee ee ee ee ww ew we we ee ee +) ~PhatypEsus. 
BRACHYCYBE. 
No species of Brachycybe have as yet been obtained from Central America. The 
probability of the existence of the genus in Mexico, however, is forcibly suggested by 
the record of B. lecontet from Georgia, Tennessee, and Arkansas, and of two others, 
B. rosea, Murray, and B. californica, Karsch, which may or may not prove identical 
with it, from California. The only representative of this group known to me, which 
appears to belong to Brachycybe, is a specimen from Corfu, identified by Verhoeff as 
Platydesmus typhlus, Daday. It is possible that all the Mediterranean species belong 
to Brachycybe and not to Platydesmus ; but if the gnathochilarium is constructed as in 
Dolistenus, this can hardly be the case. 
Synopsis of the Species *. 
a. Head without eyes [first tergal plate as under 0] . . . . . guatemalensis, Brél. 
6. Head with a pair of eyes. 
a‘. Anterior border of first tergal plate produced on each side into 
| a forwardly projecting shelf more or less covering the head, 
and separated from its fellow of the opposite side by a longi- 
tudinal cleft or an acutely triangular narrow notch. 
a’. Colour black, the keels yellowish. 
a. First tergal plate completely covering the head, the 
edges of the laminz forming a straight transverse line . moreleti, Luc. 
6°. First tergal plate not completely covering the head, the 
anterior edges of the two lamine diverging obliquely 
outwards, not forming a straight line . . . . . «. mesomelas, sp. n. 
6°. Colour brown, marbled with yellow bands and spots. 
a‘. In median dorsal line a pale stripe, which expands at 
intervals into four triangular patches; laminz of first 
tergite much smaller, separated by a triangular notch 
in the middle line . . . «© «© e+ + «© © «© ee « «marmoreus, sp. n. 
b*. Median dorsal line dark with a pale interrupted band 
on each side of it, formed of square or oblong patches ; 
lamine of first tergite large, separated in middle line 
by anarrow slit . .... 0... eee ey perpictus, sp. n. 
* Excluding P. polydesnoides,. Lucas, 
